1. Field of the Invention
The present invention relates to a micro electro mechanical system (MEMS), and more particularly, to a microenergy device capable of generating extremely precise micro energy which is the most significant characteristic required in the microenergy device.
2. Description of the Prior Art
In general, a microenergy device refers to a device for outputting the finely adjustable microenergy. The microenergy may include force, displacement, velocity, momentum, pressure, flow rate, flow velocity, temperature, heat flux, heat flow, reaction energy, etc.
According to a principle of outputting the microenergy, such a microenergy device can be classified into a piezoelectric microenergy device, an electrostatic microenergy device, electromagnetic microenergy device, and thermal expansion microenergy device, for example.
Accordingly, an MEMS field is also classified, according to a type of the microenergy to be employed, into Bio-MEMS, Power-MEMS, Micro-fluidics, RF-MEMS, Optical-MEMS and the like. Therefore, the microenergy device serves as a microactuator, a micropump and a micromirror in the fields of the Power-MEMS, the Micro-fluidics and the Optical-MEMS, respectively.
Technologies for the microenergy devices can be known in the following published documents:
“Electrostatically actuated gas microvalve based on a Ta—Si—N membrane”, Ph. Dubois, B. Guldimann, M.-A. Gretillat, N. F. de Rooij, Micro Electro Mechanical Systems, 2001, MEMS 2001, The 14th IEEE International Conference on 2001, pp. 535-538; and
“An SOI optical microswitch integrated with silicon waveguides and touch-down micromirror actuators”, Y. H. Jin, K. S. Seo, Y. H. Cho, S. S. Lee, K. C. Song, J. U. Bu, Proc. 3rd International Conference Optical MEMS 2000 (MOEMS 2000), Kauai, U.S.A. (Aug. 21-24, 2000), pp. 43-44.
As shown in FIG. 1, the conventional microenergy device is composed of an electrical modulator 1 and an analog microenergy generator 2.
The electrical modulator 1 has a function of generating electrical energy corresponding to a control signal inputted thereto and transmitting the generated electrical energy to the analog microenergy machine 2. The analog microenergy generator 2 has a function of outputting microenergy corresponding to the electrical energy inputted from the electrical modulator 1.
The conventional microenergy device is constructed in such a manner that the electrical modulator 1 which has received the input signal supplied from the outside in the form of a digital signal modulates the electrical energy supplied to the analog microenergy generator 2 according to the input signal and the analog microenergy generator 2 generates the microenergy corresponding to an amount of change in the electrical energy inputted from the electrical modulator 1.
However, there are the following three problems in obtaining the highly precise microenergy using a conventional method of operating the microenergy device.
A first one of the problems is that a magnitude of the microenergy is influenced by an error included in the electrical signal.
As an example, a case where the microenergy to be processed is actuation displacement will be discussed. In general, a lower threshold of the noise contained in the electrical signal of 10 V is 1 to 10 mV. However, a voltage should be adjusted to a degree of 10 μV in order to control the actuation displacement having a range of 1 mm and a precision of 1 nm using the electrical signal of 10 V. Thus, it cannot be achieved by a current technology.
Another problem is that a current MEMS device fabricated based on the UV has a fabrication tolerance of 0.1 to 0.5 μm. The fabrication tolerance can make it difficult to precisely adjust the microenergy.
A last problem is related to uncertainty in physical properties of materials which construct the MEMS device.
The materials which construct the MEMS device are generally formed through a thin film process. Thus, since the properties of the materials are changed depending upon the performed process and process conditions thereof, they can have an influence on the adjustment of the microenergy.